For the study, the research team analysed an international group of 2,411 patients with vitiligo. The patients were treated with a drug known as pseudocatalase activated via sunlight. Researchers noticed that the pigment of the skin and eyelashes returned.

Gerald Weissman, FASEB Journal editor-in-chief, said the same treatment could be developed to allow "repigmentation" of grey hair – or indeed to stop it going grey in the first place.

"For generations, numerous remedies have been concocted to hide grey hair but now, for the first time, an actual treatment that gets to the root of the problem has been developed."

In the mean time he said the priority was to develop a treatment for vitiligo, that can cause serious social problems for patients.

"While this is exciting news, what's even more exciting is that this also works for vitiligo," he said.

"This condition, while technically cosmetic, can have serious socio-emotional effects of people.

"Developing an effective treatment for this condition has the potential to radically improve many people's lives."

Professor Karin Schallreuter, the lead author and specialist in vitiligo, also said the important thing is to develop treatments for vitiligo.

"To date, it is beyond any doubt that the sudden loss of the inherited skin and localised hair colour can affect those individuals in many fundamental ways," she said.

"The improvement of quality of life after total and even partial successful repigmentation has been documented."